A systematic review and meta-analysis of clinical trials of thyroid hormone administration to brain dead potential organ donors*

Abstract

To review all published clinical studies of thyroid hormone administration to brain-dead potential organ donors. A search of PubMed using multiple search terms retrieved 401 publications including 35 original reports describing administration of thyroid hormone to brain-dead potential organ donors. Detailed review of the 35 original reports led to identification of two additional publications not retrieved in the original search. The 37 original publications reported findings from 16 separate case series or retrospective audits and seven randomized controlled trials, four of which were placebo-controlled. Meta-analysis was restricted to the four placebo-controlled randomized controlled trials. Whereas all case series and retrospective audits reported a beneficial effect of thyroid hormone administration, all seven randomized controlled trials reported no benefit of thyroid hormone administration either alone or in combination with other hormonal therapies. In four placebo-controlled trials including 209 donors, administration of thyroid hormone (n=108) compared with placebo (n=101) had no significant effect on donor cardiac index (pooled mean difference, 0.15 L/min/m²; 95% confidence interval -0.18 to 0.48). The major limitation of the case series and retrospective audits was the lack of consideration of uncontrolled variables that confound interpretation of the results. A limitation of the randomized controlled trials was that the proportion of donors who were hemodynamically unstable or marginal in other ways was too small to exclude a benefit of thyroid hormone in this subgroup. The findings of this systematic review do not support a role for routine administration of thyroid hormone in the brain-dead potential organ donor. Existing recommendations regarding the use of thyroid hormone in marginal donors are based on low-level evidence.